Surgical instruments and procedures for stabilizing the beating heart during coronary artery bypass graft surgery

ABSTRACT

The invention is methods and devices which a surgeon may use to stabilize the beating heart during a surgical procedure on the heart. Pursuant to the invention, a stabilizing device is introduced through an opening in the chest and brought into contact with the beating heart. By contacting the heart with the device and by exerting a stabilizing force on the device, the motion of the heart caused by the contraction of the heart muscles is effectively eliminated such that the heart is stabilized and the site of the surgery moves only minimally if at all. Typically, in separate steps, the surgeon contacts the heart with the stabilizing means, assesses the degree of movement of the anastomosis site, and exerts a force on the stabilizing means such that the. contraction of the beating heart causes only minimal excess motion at the surgery site. By fixing the position of the stabilizing means in a configuration where the motion of the beating heart is effectively eliminated, the surgeon is able to stabilize the beating heart for the duration of the procedure. The stabilizing means may be attached to a rigid support or may be attached to a semi-rigid support which is rendered motionless mechanically, chemically, or by human intervention. In certain preferred embodiments, the stabilizing means is affixed to a semi-rigid support which is caused to become rigid, by any of a variety of techniques, such that the position of the stabilizing means becomes fixed by the support, and the heart remains substantially motionless for the duration of the procedure.

[0001] Diseases of the cardiovascular system affect millions of peopleeach year and are a leading cause of death in the United States andthroughout the world. The costs to society from such diseases isenormous both in terms of the lives lost and in terms of the cost oftreating patients through surgery. A particularly prevalent form ofcardiovascular disease is a reduction in the blood supply leading to theheart caused by atherosclerosis or other condition that creates arestriction in blood flow at a critical point in the cardiovascularsystem that supplies blood to the heart. In many cases, such a blockageor restriction in the blood flow leading to the heart can be treated bya surgical procedure known as a Coronary Artery Bypass Graft (CABG)procedure, which is more commonly known as a “heart bypass” operation.In the CABG procedure, the surgeon removes a portion of a vein fromanother part of the body to use as a graft and installs the graft atpoints which bypass the obstruction to restore normal blood flow to theheart.

[0002] Although the CABG procedure has become relatively common, theprocedure itself is lengthy and traumatic and can damage the heart andcardiovascular system, the central nervous system, and the blood supplyitself. In a conventional CABG procedure, the surgeon must make a longincision down the center of the chest, cut through the entire length ofthe sternum, perform several other procedures necessary to attach thepatient to a heart-lung bypass machine, cut off the blood flow to theheart, and then stop the heart from beating in order to install thegraft. The lengthy surgical procedures are necessary, in part, toconnect the patient to a cardiopulmonary bypass machine to continue thecirculation of oxygenated blood to the rest of the body while the bypassgraft is sewn into place.

[0003] Although several efforts have been made to make the CABGprocedure less invasive and less traumatic, most techniques stillrequire cardiac bypass and cardioplegia (stoppage of the heart). Thesafety and efficacy of CABG procedure could be improved if the surgeoncould avoid the need to stop the heart from beating during theprocedure, thereby eliminating cardiopulmonary bypass and the lengthyand traumatic surgical procedures necessary to connect the patient to acardiopulmonary bypass machine to sustain the patient's life during theprocedure. In recent years, a small number of surgeons have begunperforming CABG procedures using surgical techniques especiallydeveloped so that the CABG procedure could be performed while the heartis still beating. In such procedures, there is no need for any form ofcardiopulmonary bypass, no need to perform the extensive surgicalprocedures necessary to connect the patient to a cardiopulmonary bypassmachine, and no need to stop the heart. As a result, the surgery is muchless invasive and the entire procedure can typically be achieved throughone or two comparatively small incisions in the chest.

[0004] Despite the advantages, the beating-heart CABG procedure is notwidely practiced, in part, because of the difficulty in performing thenecessary surgical procedures using conventional instruments. If specialdesigned instruments were available so that the CABG procedure could beperformed on the beating heart, the beating-heart CABG procedure wouldbe more widely practiced and the treatment of cardiovascular disease ina significant patient population would be improved.

[0005] As noted above, the CABG procedure requires that a connection forthe flow of blood be established between two points to “bypass” adiseased area and to restore blood flow to the heart. This procedure isknown as an “anastomosis.” Typically, one end of the by-pass graft issewn to a source artery with an unobstructed blood flow, such as theleft internal mammary artery (LIMA), while the other end of the graft issewn to a target coronary artery, such as the left anterior descending(LAD) artery, that provides blood flow to the main muscles of the heart.Because the beating-heart CABG procedure is performed while the heartmuscle is continuing to contract and pump blood, the anastomosis isdifficult to perform because the heart continues to move and to attemptto pump blood while the surgeon is sewing the graft in place. Thesurgical procedure necessary to install the graft in the beating-heartCABG procedure requires placing a series of sutures through severalextremely small vessels that continue to move during the procedure.Moreover, the sutures must be carefully placed so that the graft isfirmly attached and does not leak when blood flow through the graft isestablished. It is also important that the procedure be performedrapidly because the blood flow through the target coronary artery isinterrupted or reduced during the procedure to allow the graft to beinstalled without excessive blood loss. Also, the working space andvisual access are limited because the surgeon may be working through asmall incision in the chest or may be viewing the procedure on a videomonitor if the site of the surgery is viewed via a surgical scope.

[0006] A current practice is for the surgeon to place sutures throughthe heart tissue and, by exerting opposing tension on the sutures,stretch the tissue surrounding the anastomosis to partially reduce themotion of the heart while the graft is installed. This approach is farfrom ideal. Alternatively, a suction device may be attached to thesurface of the heart to fix the motion of the outer layer of surfacetissue. In such cases, a suction device typically has several portsincorporated into an instrument may be attached to the heart to apply anegative pressure to the surface tissue. The negative pressureessentially attaches the surface tissue to the apparatus thereby fixingthe position of a portion of the surface of the heart. Such devices aredescribed in co-pending application Ser. No. ______.

[0007] While the negative pressure approach may be effective in fixing aportion of the surface tissue of the heart, the negative pressureapplied to cardiac tissue can result in temporary hematomas at the sitewhere the suction ports attach to the tissue. Also, the exterior cardiactissue is fixed in a configuration defined by the shape of theinstrument and the orientation of the suction ports. While the heartcontinues to beat, the heart muscles are contracting to pump blood,which results in the muscles exerting a force directed away from theexterior tissue fixed by suction.

[0008] The beating-heart CABG procedure could be greatly improved if theheart could be stabilized during the procedure such that the motion ofthe heart, particularly at the site of the anastomosis, is minimizedeven though the heart continues to beat. If effective means forstabilizing the beating heart were available, the beating heart CABGprocedure could be performed more easily, more rapidly, more safely, andwith less trauma to the patient.

SUMMARY OF INVENTION

[0009] The advantages provided to a surgeon by the instruments andtechniques of the invention allow the beating heart CABG procedure to beperformed more rapidly with less trauma to the patient, and without CPBor cardioplegia. This invention provides an alternative approach to thesuction apparatus by providing devices and methods for stabilizing themotion of the heart using mechanical instruments specially designed toapply a stabilizing force to the heart to minimize the motion of thebeating heart during a surgical procedure. The invention enables asurgeon to readily and rapidly perform a beating-heart CABG procedurewithout the need for cardioplegia or cardiopulmonary bypass. Inparticular, the methods and devices described here enable the surgeon tostabilize the heart such that an anastomosis can be more readilyaccomplished by enabling the surgeon to attach the graft to a targetcoronary artery whose motion is minimized for the duration of thesurgical procedure.

[0010] Pursuant to the invention, a stabilizing device is introducedthrough a suitable opening in the chest to provide access to the beatingheart. By contacting the heart with the stabilizing means of thisinvention and by exerting a stabilizing force on the heart, the motionof the heart caused by the contraction of the heart muscles iseffectively eliminated such that movement of the target artery at thesite of the surgery is minimized. The remainder of the heart may beallowed to contract normally or may have additional devices in place tosupport the heart or to restrain its motion. An important advantage ofthis invention is derived from the discovery that an effective procedurecan be followed using the devices of the inventors to provide anadvantageous technique for stabilizing the beating heart. The procedurerequires exerting a stabilizing force on the beating heart using devicesconstructed as described herein. Typically, in separate steps, thesurgeon contacts the heart with the stabilizing means, assesses thedegree of movement at the site of the surgery and positions thestabilizing means proximate to the target coronary artery. With thestabilizing means in place, the surgeon applies a stabilizing force tothe stabilizing means by applying a force such that the portion of theinstrument in contact with the surface of the heart displaces thesurface of the heart a sufficient distance that the contraction of theheart does not cause either vertical or horizontal motion at the surgerysite. The stabilizing force is applied by the stabilizing means of theinvention and comprised of exerting a mechanical force onto the beatingheart at the location of the target coronary artery. Thus, an importantaspect of this invention is the discovery that the beating heart may beeffectively stabilized for the purpose of a surgical procedure by usinga specially designed instrument as described herein to exert amechanical stabilizing force on the exterior of the heart proximate tothe site of the surgery.

[0011] By fixing the position of the stabilizing means in aconfiguration where the motion of the beating heart is effectivelyeliminated, the surgeon maintains the stabilizing force on the beatingheart for the duration of the procedure. To fix the position of thestabilizing means, the means may be attached to a retractor used toseparate the ribs or tn another fixed support. Alternatively, thestabilizing means may be attached to a semi-rigid cono formable armwhich is rendered rigid by mechanically, chemically, or by humanintervention. In certain preferred embodiments, the stabilizing meanshas an adjustable shaft means which may be oriented in severaldirections and has a fixture adapted to be attached to a retractor. In apreferred technique of the invention, the surgeon first performs athoracotomy, retracts the ribs using a retractor which is locked in anopen position providing access to the beating heart. The surgeon thencontacts the surface of the heart with the stabilizing means at a pointproximate to the target coronary artery, and exerts a stabilizing forceon the stabilizing means until the site of the surgery is substantiallymotionless. At this point, the adjustable shaft means is positioned andfixed in place by attachment to the retractor thereby rendering thetarget coronary artery substantially motionless for the duration of theprocedure.

DESCRIPTION OF THE FIGURES

[0012]FIG. 1 is a means for stabilizing the beating heart having a pairof substantially planar contact members which engage the heart on eitherside of a target coronary artery to which a bypass graft is sewn.

[0013]FIG. 1 also shows the contact members attached to a shaft meanswhich may be adjustable in several directions and which may be attachedto a retractor or other fixed support structure.

[0014]FIG. 1A is detail of the shaft means and the structure of theadjustable positioning mechanisms.

[0015]FIG. 1B is a contact member having a friction means which ispreferably affixed to the bottom surface of the contact member.

[0016]FIG. 2 is an alternate embodiment of a stabilizing means having asingle shaft means associated with each contact member and where theshaft means are interconnected and can be moved independently about apivot such that the contact members spread the surface tissue of theheart proximate to the target coronary artery to increase exposure ofthe target artery at the site of the anastomosis.

[0017]FIG. 3 is a means for stabilizing the beating heart having a pairof contact members which are additionally comprised of aspring-tensioned frame having an extension that engages and spreads thetissue at the site of the surgery to better expose the coronary artery.

[0018]FIG. 4 is an inflatable means for stabilizing the beating hearthaving a sheath member with several pliable support attachmentsassociated therewith which may include or be comprised of inflatablemembers which are positioned at one or several locations surrounding theheart and may have a lumen disposed within the sheath member for theintroduction of air or a biocompatible fluid.

[0019]FIG. 5 is a means for stabilizing the beating heart comprising asystem which incorporates the retractor which spreads the ribs toprovide surgical access to the heart. The stabilizing means is comprisedof a pair of stabilizing plates which may be used together with a leverdevice to improve exposure of the target coronary artery.

[0020]FIG. 6 is a flexible, lockable arm which allows positioning inevery direction to place and orient the contact members until therequisite degree of stabilization is achieved at which point the armhaving a stabilizing means is fixed in position. The flexible, lockablearm may be attached to a retractor and is caused to become rigid whenthe entire stabilizing means is properly positioned.

[0021]FIG. 7 is a substantially planar stabilizing platform whichcontacts the heart at a site proximate to and surrounding the coronaryvessel. The platform may also have associated therewith at least oneoccluder which restricts or eliminates blood flow through an artery andan associated device for spreading the tissue proximate to theanastomosis.

[0022]FIG. 8 is a stabilizing contact member having means associatedtherewith for attaching a snap fixture or other method of attachment tothe stabilizing member such that the cardiac tissue is attached to thecontact member.

[0023]FIG. 9A is a view of the interior of the chest cavity during aCABG procedure on the beating heart with the stabilizing means operablyassociated with a retractor and being used in conjunction with othersurgical apparatus to facilitate completing the anastomosis. FIGS. 9Band 9C show the stabilizing means of the invention having beenintroduced through a thoracotomy to contact the beating heart to engagethe heart tissue on either side of a target coronary artery to which ananastomosis is sewn.

[0024]FIG. 10 is an embodiment of the stabilizing means of the inventionhaving a pair of plates operably associated with a rib retractor and asphere disposed between the plates to facilitate orientation of theshaft means.

[0025]FIG. 11 is an embodiment of the stabilizing means of the inventionhaving stabilizer bars suspended from the bottom side of a rib retractorwherein the stabilizer bars engage a ratchet means.

[0026]FIG. 12 is an embodiment of the invention having malleablesupports attached at the ends on the contact members and attached to therib retractor.

DETAILED DESCRIPTION OF THE INVENTION

[0027] This invention is surgical instruments for stabilizing-thebeating heart and methods for their use. The means for stabilizing thebeating heart are comprised of several alternative structures whichengage the surface of the heart to stabilize the beating heart duringcoronary surgery. The instruments provide the capability to exert andmaintain a stabilizing force on the heart by contacting the heart withthe stabilizing means and by fixing the position of the stabilizingmeans throughout the duration of a surgical procedure.

[0028] The instruments and methods of the invention are preferably usedfor stabilization of the beating heart during a minimally invasivecoronary artery bypass graft (CABG) operation which has been speciallydeveloped to facilitate placement of a bypass graft without cardioplegiaor cardiopulmonary bypass. Although the means for stabilizing thebeating heart can be applied in different surgical contexts, the devicesdescribed herein are most advantageously employed in a CABG procedurewherein only one or two incisions are placed in the chest. The structureof the stabilizing means may be described by several structuralembodiments which stabilize the beating heart while the minimallyinvasive surgical procedure is performed. The stabilizer means may alsoadvantageously function in a multiple component system containing aretractor, an occluder, a surgical blower or suction device, anapparatus for holding the source artery, such as a LIMA holder, or otherlike devices to enable a surgeon to more efficiently complete theanastomosis. While the devices disclosed herein each use mechanicalmeans to stabilize the beating heart, certain embodiments are designedto operate on the entire heart while others have more localized effectand may be applied to the area immediately proximate to a structure suchas the target artery of the anastomosis. In each instance, the beatingheart is effectively stabilized at the area where a surgical procedureis to be performed. Surgical access to the beating heart may be achievedby several conventional cardiac surgical procedures which have beendeveloped for traditional bypass surgery. The surgeon may obtain theadvantages provided by the invention in any procedure where the bypassis achieved on the beating heart. When access to the beating heart isachieved by a sternotomy, the length of the sternum is separated toexpose the surface of the heart. Preferably, the surgeon takesadditional measures to restrict the movement at the entire heart withinthe chest cavity. For example, an inflatable cushion with straps orlaces may be inserted beneath or surrounding the heart. Additionally,when the pericardium is available, the pericardium may be incised andused to position the beating heart. When the pericardium is available,the surgeon can use the pericardium to raise and rotate the beatingheart within the chest cavity and maintain the position by suturing thepericardium to the periphery of the incision.

[0029] In the preferred embodiment, minimally invasive access to thebeating heart is achieved by a thoracotomy, which is usually created inthe left side of the chest by a vertical incision between the ribs,insertion of a retractor between the ribs, followed by spreading of theribs and securing the retractor in an open position to provide access tothe source artery and the target coronary artery. The use of thepericardium to position the beating heart as described above isparticularly advantageous when the less invasive thoracotomy is used toprovide access to the heart. An incision is created in the pericardiumwhich is then sutured to the periphery of the thoracotomy. In thisconfiguration, the pericardium acts as a restraining sac to keep thebeating heart in a desired orientation to achieve the anastomosis. Themeans for stabilizing the beating heart is introduced through theopening created by the thoracotomy and is brought into contact with theheart. The surgeon applies a stabilizing force to the heart via thestabilizing means which may then be fixed in place by attachment to afixed support. When the rib retractor or platform is fixed in an openposition to expose the heart, the retractor platform may also provide anadvantageous stable support structure to which the stabilizing means maybe affixed. When the position of the stabilizing means is fixed byattachment to a stable support or to the retractor platform, thestabilizing force is maintained for the duration of the procedure.

[0030] Although the particular source and target artery of theanastomosis are determined clinically, common minimally invasive bypassprocedure on the beating heart comprises an anastomosis which forms aconnection between the left internal mammary artery (LIMA) as the sourceartery and the left anterior descending artery (LAD) as the targetartery. The LIMA to LAD anastomosis is used as an example herein but itis readily appreciated that the techniques and instruments describedherein may be applied to other procedures depending on the clinicaldiagnosis. To complete the anastomosis, the surgeon must dissect aportion of the LIMA by separating it from the internal chest cavity.Once dissection of the LIMA is achieved, the surgeon may attach thedissected LIMA to the target cardiac artery, in this example, the LAD.In this example, the stabilizing means of this invention would be usedto stabilize the beating heart during at least the portion of theprocedure during which the surgeon completes the anastomosis to the LAD.

[0031] The structure of the portion of the stabilizing means whichcontacts the heart includes an inflatable member, a platform which maybe substantially planar or which may be contoured to fit conformingly onthe surface of the heart, one or more contact members which exert astabilizing force on the heart proximate to the site of the anastomosis,a pair of contact members which may be plates or rectangular memberswhich are placed on either side of the target coronary artery at thesite of the anastomosis and which may have a friction or tissuespreading means associated therewith. The stabilizing means may alsoinclude a shaft means having several alternative embodiments tofacilitate adjusting the position and orientation of the instrument. Forexample, the shaft means may have an adjustable length and the axis ofthe shaft means may have at least one ball joint disposed within itslength such that the orientation of the shaft means relative to anotherstructure such as the contact members on the retractor may becontinuously varied. As is apparent from the description of the severalembodiments, each of the individual embodiments described andillustrated herein has discrete components and features which may bereadily separated from or combined with the features of any of the otherseveral embodiments without departing from the scope of the invention.

[0032] Referring to FIG. 1, a stabilizing means is comprised of one ormore, and preferably two, contact members 1, which are attached to arigid, or semi-rigid connecting shaft 2 which is in turn connected toshaft means 3. The contact members 1 may be substantially planar or maybe slightly curved to conform to the shape of the heart. The contactmembers 1 may have any of several alternate shapes including cylindricalmembers formed into a U-shape or may comprise a pair of substantiallyparallel members spaced apart in a parallel configuration such that atarget artery can be positioned between the contact members. The shapeof the contact members may be varied depending on the clinicalassessment by the surgeon, the design of the other features of thestabilizing means, or the design of other instruments used to completethe anastomosis. In some embodiments, as described herein, the. contactmembers 1 may have apertures, openings or attachments to facilitateconnection with sutures or other devices to achieve the requisitestabilization. In a preferred embodiment, a pair of substantially planarrectangular contact members 1 are attached at one end to a continuousconnecting shaft 2 and are oriented in a substantially parallel fashionsuch that a target cardiac artery is positioned therebetween and passesalong the length of the contact members 1 when the stabilizing meansengages the heart. See FIGS. 9A-C. While the contact members 1 may eachbe connected to the connecting shaft 2 at one end, with the connectingshaft 2 operably attached to shaft means 3, the configuration of theconnecting shaft 2 relative to the contact members 1 may be altereddepending on the configuration of the contact members 1 and the clinicalaspects of the procedure. For example, the connecting shaft may becontinuous to connect with the contact members 1 without touching theartery or may include an additional member which may be operated tocontact the target artery positioned between the contact members 1, seeFIG. 8, to occlude the passage of blood through the target artery. Thecontact members 1, connecting shaft 2 and shaft means 3 may be composedof any non-toxic material such as a biocompatible plastic or stainlesssteel, having sufficient tensile strength to withstand a stabilizingforce exerted on the heart via manipulation of the shaft means 3 tocause the contact members 1 to exert a stabilizing force on the beatingheart.

[0033] The shaft means 3 may be a simple rigid post or may be comprisedof a multi-component system designed to be adjustable in length andorientation at least one point along its length. Thus, the length of theshaft means 3 and the orientation of the contact members 1 at the distal(lower) end of the shaft means 3 can be altered by the surgeon.Preferably, the length and orientation at the shaft means 3 relative tothe contact members 1 can be adjusted by controls located at theproximate (upper) end of shaft means 3. This design provides theadvantage that the surgeon can introduce the stabilizing means to thebeating heart by placing the contact members 1 on the surface of theheart, exerting a stabilizing force, and then locking the contactmembers 1 in place relative to the shaft means 3. Furthermore, thesurgeon may then lock the shaft means 3 into a fixed position byattachment to a stable support such as the retractor, therebymaintaining the stabilizing force for the duration of the procedure. Inone embodiment, the shaft means 3 has a housing 11 whose overall lengthis adjustable by a telescoping release 4 operated by an annularthumbscrew 10 which tightens about the housing 11. The position andorientation of the contact members 1 relative to the shaft means 3 isadjustable by virtue of a locking ball joint 5 which is interposedbetween the connecting shaft 2 and which is located at the distal end ofshaft means 3. The locking ball joint 5 allows the position of the shaftmeans 3 to be positioned with three degrees of freedom relative to thecontact members 1.

[0034] Referring again to FIG. 1, a locking ball joint 5 is provided byincluding a block 6 within the shaft means 3 which conformingly contactsthe ball joint 5 and fixes the position of the ball joint 5. Block 6 iscompressed against ball joint 5 when a threaded push block 7 isconnected to a long allen 9 is actuated by means such as a thumbscrew 8at the upper end of the shaft means 3. In operation, a rotation of thetop thumbscrew 8 loosens the lower ball joint 5 to allow continuouspositioning of the shaft means 3 relative to the contact members 1, anda counterrotation locks the ball joint 5 into place, fixing the positionof the contact members 1 relative to shaft means 3.

[0035] The upper end of shaft means 3 may also have associated therewithan upper ball joint 13 such that the shaft means 3 can be oriented withthree degrees of freedom relative to a fixed support such as aretractor. The position and orientation of the shaft means 3 may thus befixed relative to the stable support by a locking latch 14 or otherconventional mechanism which prevents movement of the upper ball joint.Either the shaft means 3 or the retractor may contain the locking latch14 surrounding the upper ball joint 13 or any like fixture to firmlyattach the shaft means 3 to a stable support, e.g., an anchor portion 15extending from the retractor (not shown).

[0036] Referring to FIG. 1B, the contact members 1 preferably havefriction means 4 associated with their bottom surface 5 such that thecontact members 1 more securely engage the beating heart when astabilizing force is exerted on the shaft means 3. The friction means 4preferably comprises a textured surface covering the bottom surface 5 ofthe contact member 1, and may be comprised of several bio-compatiblesubstances such as a textured rubber, textured or ridged aluminum,stainless steel or the like.

[0037] As noted above, at the upper end of the shaft means 3, the shaftmeans 3 may be attached to a fixed support, such as by anchor portion15, which may be any surface or structure which does not move with thebeating heart. For example, the shaft means 3 may be attached to afixture on the retractor system used to spread the ribs for access tothe heart or may be attached to a fixed structure such as the surgicaltable or associate aperture which is not connected to the patient. In apreferred embodiment, the shaft means 3 is directly attached to acomponent of the retractor system which is designed to receive the shaftmeans 3 and to maintain the position and orientation of the shaft means3 during the procedure.

[0038] The shaft means 3 may also be attached, to or comprised of, aconformable arm which is used to position the stabilizing means againstthe heart and then to lock the stabilizing means in place once astabilizing force has been exerted. The conformable arm is flexible andlockable and may have several configurations including a plurality oflinks, segments, or universal joints in serial configuration and havinga cable fixture passed through the interior of the links which cause theentire conformable arm to become rigid by tightening the cable fixture.Also, the conformable arm may be comprised of a synthetic gel or polymercontained within a conformable cylindrical housing and which becomesrigid upon exposure to light or heat, such as the commercially availableDymax 183-M. Where the shaft means 3 is further comprised of theconformable arm, the conformable arm may be attached directly to theconnecting shaft 2 or the contact members 1.

[0039] Referring to FIG. 2, the stabilizer-means may also be comprisedof a single shaft means 3 connected to each contact member 1. In apreferred embodiment, the shaft means 3 are interconnected at anintermediate pivot point 16 which permits the contact members 1 to becontinuously positioned in parallel fashion relative to one another. Theproximate (upper) portion of the individual shaft means 3 may have gripsadapted to be grasped by the hand or may have an anchor portion 15 forattachment to a retractor or other fixed support. As with the otherembodiments described herein, the length of the shaft means 3 may beadjustable by a conventional telescope configuration. In such aconfiguration, a first shaft 18 has a partially hollow segment 17adapted to receive the complimentary portion of the second shaft 19.Either first 18 or second 19 shafts may be connected to the contactmembers 1 and may each have a conventional locking mechanism (notshown). The shaft means may also have a tensioning spring mechanismhaving an axis 21 which is displaced between a portion of the shaftmeans 3 affixed to the contact members 1 and the remainder of the shaftmeans 3. In this configuration, the contact members 1 remain tensionedagainst the heart proximate to the anastomosis site when the proximalend of the shaft means 3 is affixed to a stable support. The shaft meansmay also comprise an interlocking mechanism 18 to fix the position of asingle shaft 18 relative to the other. This embodiment also preferablyhas a friction means 4 as described above attached to each contactmember 1. An additional advantage of this embodiment is derived from thecapability to move the contact members 1 apart from one, another in aparallel configuration. Thus, the contact members 1 can first bepositioned to engage the surface of the heart tissue, followed by theapplication of a stabilizing force in combination with spreading of theproximate (upper) end of the shaft means 3. Application of a stabilizingforce causes the tissue on either side of the target artery to bestabilized. By coincidentally spreading the proximate portion of theshaft means 3, the tissue engaged by the contact members 1 is stretchedto provide stabilization and improved exposure of the target coronaryartery.

[0040] Referring to FIG. 3, the contact members 1 may be furthercomprised of a spring-tensioned frame 21 having a movable frameextension 22 which may have pins or an associated friction means 4 toengage the tissue proximate to the target artery. The movement of theframe extension 22 is tensioned by a spring means 23 which draws theframe extension 22 toward the contact member 1 after the frame extension22 has been manually positioned to engage the tissue. The use of thisembodiment of the invention is the same as is described for the otherembodiments herein, with the frame extension 22 providing improvedexposure of the target artery. As with the other embodiments of theinvention disclosed herein, the contact members 1 may be attached at oneend by a connecting shaft 2 which is attached to a shaft means 3 asdescribed above. The connecting shafts 2 may also be positioned relativeto one another by a conventional threaded post 24 with a positioningthumbscrew 25.

[0041] Referring to FIG. 4, this embodiment of the stabilizing means iscomprised of an elongated sheath member 26 which wraps around the heartin a strap-like fashion to restrict the motion of the heart. Thisembodiment is particularly useful when access to the beating heart isprovided by a sternotomy. The sheath member 26 is positioned to surroundthe heart and manipulated so that each end of the sheath member 26extends out of the chest cavity through a the stemotomy. If desired, atleast one end of each sheath member 26 is attached to the retractor tosecure the position of the sheath member 26. The sheath member 26 mayhave a plurality of support attachments 27 which engage the exterior ofthe heart to hold it in place. At the point where the supportattachments 27 contact the surface of the heart, the support attachments27 may have friction means 4 attached to the surface which is in directcontact with the heart. The support attachments 27 may have or becomprised of inflatable members 28 which cushion the heart against thesheath member 26, and absorb the motion of the heart while it isstabilized. Where the sheath member 26 has a plurality of inflatablemembers 28, the sheath member 26 is preferably further comprised of atleast one lumen 29 for introduction of air or a biocompatible fluid tothe inflatable members 28, which may be inflated separately orsimultaneously. In the former instance, a separate lumen 29 is providedfor each inflatable member 28. The insertion of the sheath member 26into the chest cavity should be performed while the inflatable members28 are deflated and is achieved manually or by a conventional guideand/or guidewire. Each of the support attachments 27 may be permanentlyattached to the sheath member 26 or may slide along the length of thesheath member 26. Alternatively, alone or in combination with at leastone other inflatable member 28, an inflatable member 28 may bepositioned immediately proximate to the target coronary artery toachieve a more localized stabilization. The inflatable member 28 ispositioned to lie next to, or may surround, the target coronary arteryand may have openings or apertures placed in the body of the memberthrough which surgical procedures are performed.

[0042] Referring to FIG. 5, the stabilizer means may comprise at leastone stabilizer plate which is attached to a stable support and which maybe used with a lever member for improving exposure at the target arterywhile the anastomosis is completed. In this embodiment, the means forstabilizing the beating heart comprises a left and right stabilizingplate 30, 31 which are oriented to exert a downward force on the tissueat either side of the target artery at the anastomosis site and whichmay be substantially planar or may be curved to conform to the surfaceof the heart. One or both of the stabilizing plates 30, 31 may have anedge 27 deflected downward along its length so that the edge 27depresses the tissue proximate to the artery to increase the exposure ofthe artery during the completion of anastomosis. Preferably, the edge 27of the stabilizing plates 30, 31 has a separate lever member 33 runningsubstantially parallel to the artery and on both sides thereof. The topportion of each lever member 33 contacts the underside of thestabilizing plates 30, 31. In this embodiment, the lever member 33 issubstantially cylindrical, traverses the stabilizing plate along itslength, and is oriented to be parallel to the edge 27 of the stabilizingplate 30, 31. The lever member 33 is fixed in place, and may be affixedto the heart by a suture. In such a configuration, each of thestabilizing plates 30, 31, which is in contact with the lever member 33along its length, contacts the heart such that the edge 27 depresses thetissue on both sides of the target coronary to restrict the movement ofthe beating heart. The stabilizing plates 30, 31 can be attached to oneanother or can move independently as desired.

[0043] Opposite the edge 32, at a point separate from the lever member33, the stabilizing 30, 31 plate is connected to a shaft means 3 whichholds the stabilizing plate 30, 31 in position and which may bemanipulated relative to the lever member 33 to cause the edge 27 toengage the heart. The shaft means 3 is preferably affixed to eachstabilizing plate 30, 31 at a point opposite the edge 27 and removedfrom the point where the lever member 33 contacts the stabilizer plate30, 31 at a location to maximize leverage when the stabilizer plates 30,-31 are drawn upwards at the point of attachment of the shaft means 3.The shaft means 3 may be constructed as described elsewhere herein andshould be of sufficient length to facilitate manipulation of the shaftmeans 3 by the surgeon. As noted, the shaft means may also be attachedto the retractor to fix movement of the stabilizing plates 30, 31 duringthe procedure.

[0044] In a preferred embodiment, the length of the shaft means 3 isadjustable relative to the retractor or other stable support. Forexample, the shaft means 3 may be telescopic as described above or maybe comprised of a hollow post 34 which receives a rigid shaft 35 whichis in turn fixed to the retractor. The rigid shaft 35 may also besubstantially hollow and may have a suture or other line 36 passedtherethrough and which also passes through the length of the hollow post34. In this configuration, one end of the suture or line 36 is attachedto the stabilizing plate 30, 31 and the other end extends through thehollow post 34 or the rigid shaft 35 to a position where it may bemanipulated by the surgeon. The position of the stabilizing plate 30, 31may thereby be remotely actuated. By drawing tension on the suture orline 36, the stabilizing plate 30, 31 pivots about the lever member 33and the edge 32 of the stabilizer plates 30, 31 depress the tissue oneither side of the target artery.

[0045] Referring to FIG. 6, this embodiment of the invention is a meansfor stabilizing the beating heart wherein the shaft means is comprisedof a flexible, lockable arm 37 having a plurality of interconnectinglinks 38 which allow positioning of the flexible arm 37 in everydirection until the desired configuration is achieved at which point theflexible arm 37 may be locked into fixed configuration by tightening acable fixture (not shown) attached to a cable 39 running axially throughthe interconnecting links 38. Each interconnecting link is comprised ofa ball portion 38 a and a receiving portion 38 b such that the ballportion 38 fits conformingly within the receiving portion 38 b. Theproximate (uppermost) end of the flexible, lockable arm 37 can beattached to a stable support, or to the retractor. In a preferredembodiment, the flexible, lockable arm 37 is a series of interconnectinglinks 38 having a cable 39 running through the center of eachinterconnecting link 38 such that when tension is exerted on the cable39, the flexible, lockable arm 37 is fixed in a rigid position. FIG. 6also shows an embodiment of the invention wherein the contact members 1are comprised of a pair of substantially parallel elements 1 a, 1 bwhich are positioned to receive a simple snap fixture 40 which isaffixed to the surface of the heart. In this embodiment, the snapfixture 40 is positioned between the two parallel elements 1 a, 1 b ofthe contact member 1, in order to fix the position of the heart tissuerelative to the contact members 1. As in the above embodiment, thecontact members 1 are preferably oriented in a substantially parallelfashion with the target artery of the anastomosis passing therebetween.The snap fixtures 40 are affixed to the heart by a suture, wherein thesuture line 41 may then also be attached to the contact member 1 via anotch, which may form a one-way locking mechanism to secure the sutureline 41, or may be attached to a circular. post disposed in the body ofthe contact member 1. The suture line 41 then may be tied through thenotch or to the post in the contact member 1 to more tightly secure theheart to the contact member 1. An additional advantage of thisembodiment is that the stabilizing means is actually affixed to thecardiac tissue via the suture line 41, such that when the heart ismoving laterally or downward the artery being stabilized remainsimmobile.

[0046] Referring to FIG. 7, a stabilizing means 60 is comprised of asubstantially planar and substantially rigid surface 62 having acentrally disposed opening 61 in which the target artery of theanastomosis is positioned longitudinally through the opening. At eitheror both ends of the centrally disposed opening 61, an occluder 63extends below the surface 62 and engages the target artery tosubstantially reduce or eliminate the flow of blood through the artery.The occluder is a rigid member having a smooth outer surface forcontacting and depressing the target artery without damaging the tissue.The planar surface 62 of the stabilizing means also has an aperture 64comprising an opening which traverses the entire planar surface 62 sothat the anastomosis can be passed through the aperture 64 when theanastomosis is completed. The planar surface 62 may also provide amounting surface for springed tissue retractors 65 comprising a coiledspring 66 attached to the planar surface at one end and having a hook orpin 67 at the opposite end to engage and spread the tissue proximate tothe anastomosis site to improve the exposure of the target artery. Theplanar surface 62 is attached to a post 69 which may be attached to astable support such as the rib retractor as shown in FIG. 9b. The planarsurface 62 may also have at least one port 70 for receiving a sutureline.

[0047] Referring to FIG. 8, the stabilizing means may have operablyassociated therewith an artery occluder 42, which is preferably attachedto the contact members 1 or to the connecting shaft 2. The arteryoccluder 42 may comprise a semi-rigid member which has a blunt portion43, which may be positioned such that the blunt portion 43 engages thetarget artery 55 and compresses the target artery 55 to a point causingocclusion of the target artery 55 passing between the contact members 1such that the blood flow through the artery is substantially reduced oreliminated. Preferably, the occluder 42 has a shaft portion 44 whichtraverses the connection shaft 2 such that the blunt portion 43 of theoccluder 43 may move from above the level of the target artery 55 to apoint sufficient to occlude the blood flow.

[0048] Referring to FIG. 9A, the means for stabilizing the beating heart54 of the invention is shown in use together with a rib retractor 50 andadditional apparatus 51, 52 which may be used during the beating heartCABG procedure. In use, the blades 53 of the retractor separate theribs, thereby providing an access space for the introduction of surgicalinstruments, including the stabilizing means 54 of the invention. Thestabilizing means 54 is thus brought into contact with the heart suchthat the contact members are proximate to the target artery 55. Once thestabilizing force has been exerted, sufficient to minimize the motion ofthe beating heart, the stabilizing means 54 is fixed in place,preferably by attachment to the rib retractor 50.

[0049] Referring to FIG. 9B, the stabilizing means 54 is an embodimentsubstantially as described above and shown in FIG. 1 which is comprisedof a pair of rectangular, substantially planar contact members 1 whichare placed proximate to a target artery 55. The shaft means 3 isconformable such that it may be conveniently attached to the ribretractor 50. As shown in FIG. 9B, the surgeon may readily adjust theorientation and positioning of the contact members 1 relative to theshaft means 3 while the stabilizing means 54 is in continuous contactwith the heart by manipulating the thumbscrew 8 at the proximal end ofthe instrument.

[0050]FIG. 9c shows a later stage of the procedure at a point where theanastomosis is being completed by suturing at target artery 55. Thestabilizing means 54 thus maintains a stabilizing force at theanastomosis site for the duration of the procedure.

[0051] Referring to FIG. 10, as noted above, attachment to a ribretractor is a preferred technique for fixing the position andorientation of the stabilizing means. The stabilizing means of theinvention may therefore advantageously attached to a fixture attached toa rib retractor 50 or may be configured to be directly incorporated intothe body of a portion of the rib retractor 50.

[0052] A surgical rib retractor 50 is generally comprised of a body 54having blades 53 attached thereto, which engage the ribs and spread theribs when the retractor 50 is operated to move the blades 53 apart fromone another. The space created by the retracted blades 53 providesaccess to the heart. Thus, once the retractor 50 is locked into the openposition, the stabilizing means may be applied to the heart and astabilizing force maintained at the site of the anastomosis by fixingthe position and orientation of the shaft means 3 relative to the ribretractor 50. Referring to FIG. 10, the shaft means 3 traverses thewidth of the body 54 of the retractor 50 and is held in place by anupper plate 57 and a lower plate 58 having circular openings 59 thereinthrough which the shaft means 3 passes and which maintain the position 6f a sphere 56 positioned between the upper plate 57 and lower plate 58.The size of the openings 59 is larger than the diameter of the shaftmeans 3 but smaller than the largest diameter of the sphere 56. Thus,the shaft means 3 passes through the sphere 56 and may pivot about apoint approximately at the center of the sphere 56.

[0053] Referring to FIGS. 11 and 12, because the available access andworking space for the surgeon may be limited, certain embodiments of theinvention may be contained substantially within the chest cavity.Preferably, the stabilizing means is connected to the bottom of the ribretractor 50 on each side of the opening created by spreading the ribsusing the rib retractor 50.

[0054] Referring to FIG. 11, rib retractor 50 is shown in an openposition whereby blades 53 engage and spread the ribs. A pair ofstabilizing bars 72 having a conventional ratchet means 73 attached atthe end thereof are positioned beneath the retractor. The ratchet means73 is comprised of a plurality of teeth 74 on the stabilizing bars 72and a ratcheting aperture 75 permitting one-way passage of thestabilizing bars 72 unless released by a release mechanism. Thestablizing bars 72 are curved downward such that as the bars areadvanced through the ratchet means 73, the lowermost portion 76 of thestablizing bars 72 engages the beating heart proximate to theanastomosis site.

[0055] Referring to FIG. 12, the orientation of the portion of thestabilizing means which engages the heart relative to the rib retractor50 is similar to the embodiment shown in FIG. 11. In this embodiment, acontact member 1 is attached on opposite ends to at least two malleablesupports 80 which are in turn attached to the rib retractor 50. Themalleable supports 80 are preferably made of stainless steel bands whichare woven in a mesh or have a repeating serpentine configuration toallow for substantial expansion within the chest cavity. Thisconfiguration yields a malleable support 80 with sufficient tensilestrength to maintain a stabilizing force at the anastomosis site whileallowing the surgeon to manipulate the malleable supports within thechest cavity to achieve the desired orientation relative to the beatingheart.

[0056] The particular examples set forth herein are instructional andshould not be interpreted as limitations on the applications to whichthose of ordinary skill are able to apply this invention. Modificationsand other uses are available to those skilled in the art which areencompassed within the spirit and scope of the following claims.

1. A method to stabilize the beating heart comprising the steps of:contacting at least one section of the beating heart with a stabilizingmeans, exerting a force on the stabilizing means.
 2. The method of claim1 wherein the at least one section of the beating heart is the targetartery of an anastomosis.
 3. The method of claim 1 wherein thestabilizing means is comprised of two substantially planar contactmembers.
 4. The method of claim 2 wherein the contact members furthercomprise a friction means on a bottom surface of the contact member. 5.The method of claim 1 further comprises attaching the stabilizing meansto a fixed support to maintain the stabilizing force while ananastomosis is completed
 6. The method of claim 5 wherein the stablesupport is a surgical rib retractor.
 7. A method to install a coronaryartery bypass graft from a source artery to a target coronary arterywhile the heart is beating comprising the steps of: 1) providing anaccess space to the beating heart by a surgical procedure selected fromthe group consisting of a thoracotomy and a sternotomy, 2) introducing astabilizing means through the access space, 3) contacting the surface ofthe beating heart proximate to the target artery at an anastomosis witha stabilizing means, 4) exerting a stabilizing force on the beatingheart by positioning the stabilizing means, 5) restricting blood flowthrough the target artery while allowing the heart to continue to beat,6) sewing an anastomosis to the target artery, 7) re-establishing bloodflow through the target artery.
 8. A device for use in a cardiovascularsurgery on the beating heart comprising: a means for stabilizing thebeating heart comprising contact members shaped to engage the surface ofthe beating heart, said contact members attached to a shaft means. 9.The device of claim 8 further comprising an attachment for anchoringsaid shaft means to a stable support.
 10. The device of claim 9 furthercomprising friction means on the bottom surface of said contact members.11. The device of claim 10 wherein said shaft means is comprised of arigid shaft having a push block affixed at the end thereof, wherein saidpush block engages a ball joint proximate to said contact members. 12.The device of claim 11 wherein the rigid shaft is operably connected toa fixture at the proximal end of the device,
 13. The device of claim 8wherein said shaft means is further comprised at a telescope releasemechanism surrounding a housing.
 14. The device of claim 8 wherein saidcontact member has a frame, a spring mechanism, and a frame extensionoperably connected to said frame and said spring mechanism.
 15. Thedevice of claim 8 wherein said shaft means is connected to a singlecontact member.
 16. The device of claim 15 having a pair of shaft meansinterconnected by a pivot at an intermediate point of said shaft means.17. The device of claim 15 wherein the said shaft means is adjustablealong its length by continuous positioning of a first portion of saidshaft means which engages a second portion and moves slidably inrelation thereto.
 18. The device of claim 17 wherein said shaft means isfurther comprised of a spring mechanism disposed between said first andsecond portions of said shaft means and wherein said spring mechanismsurrounds a rigid shaft connected to one of said first and second shaftmembers.
 19. A device for use in cardiac surgery comprising: means forstabilizing the beating heart comprising a sheath member having supportattachments positioned along its length.
 20. The device of claim 19wherein the support attachments are inflatable.
 21. The device of claim20 wherein the sheath member has at least one lumen connected to saidinflatable support attachments.
 22. The device of claim 19 incombination with a rib retractor wherein a portion of said sheath memberis attached to said retractor.